Engine component steel containing small amounts of chromium and nickel

ABSTRACT

AN INTERNAL COMBUSTION ENGINE COMPONENT HAVING AT LEAST THE BEARING SURFACE OF A HARDENABLE FERROUS ALLOY CONTAINING BOTH TITANIUM AND TUNGSTEN IN CONTROLLED RANGES GIVING SYNERGISTIC RESULTS IN WEARABILITY.

United States Patent Ofice ENGINE COMPONENT STEEL CONTAINING SMALLAMOUNTS OF CHROMIUM AND NICKEL Kenneth E. Kueny, North Muskegon, Mich.,assignor to Johnson Products Inc., Muskegon, Mich. No Drawing. Filed May7, 1970, Ser. No. 37,015 Int. Cl. C22c 39/20 US. Cl. 75-128 5 ClaimsABSTRACT OF THE DISCLOSURE An internal combustion engine componenthaving at least the bearing surface of a hardenable ferrous alloycontaining both titanium and tungsten in controlled ranges givingsynergistic results in wearability.

BACKGROUND OF THE INVENTION This invention relates to engine components,and more particularly to engine components having greatly superiorwearability.

In my Patent 3,370,941 is disclosed a tungsten containing cast ironalloy having beneficial hardness qualities. This alloy has demonstratedmarkedly better characteristics compared to conventional hardenableiron, for high compression engines.

Consequently, this material has proven to be a significant advance inthe auto industry.

SUMMARY OF THE INVENTION Subsequent to the invention in the above notedpatent, it was discovered that by the addition of a controlled amount oftitanium to the novel tungsten alloy, with modification of this alloy tocontrolled component ranges, unique synergistic wearabality resultsoccur. The novel alloy is extremely effective in high compressionengines. Its wearability is unexpectedly three times greater than eventhe alloy of the above mentioned patent, hence many times greater thanconventional hardenable iron. Although my Patent 3,472,651 teaches of atitanium containing hardenable iron, it was never guessed that thecontrolled incorporation of titanium and tungsten would have thesynergistic results experienced.

It therefore is an object of this invention to provide an enginecomponent material having highly unusual wearability, many times greaterthan hardenable iron, yet capable of being readily founded by castinginto sand molds, shell molds, CO molds or permanent molds. It has beenfound particularly useful for components such as tappets and camshafts,but can be used for others where friction wear is a problem.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Basically the engine componentalloy is a hardenable iron composition as follows:

Element: Percent by weight Total carbon 3.00-3.60 Silicon 2.00-3.00Manganese 0.70-1.25 Phosphorous a 0.20 max. Sulfur a 0.10 max. Nickel0.15-0.70 Chromium 0.40-l.25 Molybdenum 0 -070 Titanium 0 10-100Tungsten O.50-l0.0 Iron Balance Impurity.

Patented Dec. 14, 1971 The phosphorous and sulfur elements are normalimpurities which are almost invariably present in these ferrous alloys.They are not required.

The controlled percentages of titanium and tungsten are essential to thecomposition. It is by carefully controlling the composition to thisrange that the surprisingly high wearability results.

A preferred specific composition in the above noted range is as follows:

Element: Percent by weight Total carbon 3.50 Silicon 2.42 Manganese 0.82Phosphorous a 0.09 Sulfur a 0.03 Nickel 0.21 Chromium 0.72 Molybdenum0.34 Titanium 0.19 Tungsten 3.20 Iron Balance Impurity.

This composition, when tested for tappets and camshafts, for example,showed an excellent initial and retained hardness and demonstrated awearability unexpectedly three times greater than the tungsten bearinghardenable iron alloy in the above identified Patent 3,370,941. Sincesuch tungsten alloy has hardness and wearability characteristicsmarkedly greater than conventional hardenable iron alloys, the value ofthese present synergistic results are clearly evident. The materialretains its hardness at greatly elevated temperatures, even up to about900 F.

Preferably the complete engine component, e.g. tappet, camshaft, rockerarm, or other, is formed of the novel alloy, but at least the bearingsurfaces thereof are of the novel alloy.

The components may be cast by normal casting techniques wherein thematerial is melted by any standard melting method, then poured intosuitable molds, such as sand molds, shell molds, carbon dioxide molds,or permanent molds, with or without chill plates as of carbon. It may behardened by normal heat training techniques such as those conventionallyused on hardenable iron for such components, a typical heat treatmentincluding heating to 1575 F., holding forthirty minutes, then quenchingin oil. It is conceivable that minor variations may be made within theconcept presented, with the invent-ion being limited only by the scopeof the appended claims and the reasonable equivalents thereto.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows.

1. An internal combustion engine component comprising a body having atleast a bearing surface of a hardenable ferrous alloy consistingessentially of the following composition:

phorous impurities) Balance 2. The component of claim 1 being a tappet.

3. The component in claim 1 being a camshaft.

4. The component in claim 1 being a rocker arm.

5. The component in claim 1 substantially of the following composition:

Element: Percent by weight Carbon 3.50 Silicon 2.42 Manganese 0.82Nickel 0.21

Chromium 0.72

Molybdenum 0.34 Titanium 3.20

Tungsten 0.19

Iron (plus minor sulfur and phosphorous impurities) Balance ReferencesCited UNITED STATES PATENTS 10 HYLAND BIZOT, Primary Examiner PMOSOSTATES PATENT @FFTCE @EETTTTQATE QT @QRREQTTGN- Patent Non 3,627,515Dated December 14, 1971 n i l Kenneth E. Kueny It ceriii'iwji that errorappears in the above-identified patent e124; than; said Letters Patentare hereby corrected as shown below:

Claim 5, line 11; delete 5;:20 and insert "0.19"

line 12; delete 0.19 and insert "3.20".

Signed and sealed this 15th day of January 197M.

( SEAL) Attest:

EDWARD M. FLEI'CHER,JR. RENE Da TEG-TMEYER Attest'ing Officer ActingCommissioner of Patents

